Note: Several readers have asked me to recommend brands of high quality canned tomatoes. But without knowing where you are and where you shop this is kind of hard to do. Suffice it to say that most brands of San Marzano tomatoes are better for sauce than any other type of canned tomato. Although doubtless some are better than others.
Yesterday I used Cento brand tomatoes and they were great (about 2 bucks for a 35 oz can). They aren't from San Marzano but they're pretty damned good.
I've never been impressed with canned tomatoes from Ca, Israel, or South America. But I suppose that one day I'll be surprised.
...This may be the surprise that I anticipated. Michael Ruhlman recommends Muir Glen tomatoes.
I'm guessing that they are Ca.